This photo released, Dec. 8, 2011, by the Iranian Revolutionary Guards, claims to show US RQ-170 Sentinel drone which Tehran says its forces downed, as the chief of the aerospace division of Iran's Revolutionary Guards, Gen. Amir Ali Hajizadeh, right, listens to an unidentified colonel, in an undisclosed location, Iran.

U.S. Defense Secretary Leon Panetta scoffed at the Iranian government's claim that it had recovered data from a downed U.S. spy drone and made a working copy of the spy craft.

"I don't want to get into the particulars of that program," Panetta told reporters during a flight to Bogota, Colombia Monday, "but I think I can tell you based on my experience that I would seriously question their ability to do what they say they have done."

The U.S. stealth drone, an RQ-170 Sentinel, was on a mission for the CIA when fell into the hands of the Iranian military in December 2011. Iranian authorities, who displayed the craft on television, claimed they had brought the drone down electronically after it entered Iranian airspace, but U.S. officials said it had been flying over Western Afghanistan when its operators lost control.

On Sunday, Iranian officials claimed publicly that they had begun building a copy of the Sentinel, had broken its internal codes and extracted detailed data.

"The Americans should be aware to what extent we have infiltrated the plane," said Brig. Gen. Amir Ali Hajizadeh. "Our experts have full understanding of its components and programs."

Hajizadeh claimed that the accessed data showed the drone had flown over Osama bin Laden's compound in Abbottabad, Pakistan in April 2011, two weeks before the al Qaeda leader's death in a U.S. raid, and that it had been sent back to California twice in 2010 for repairs.

"Had we not accessed the plane's software and hard discs, we wouldn't have been able to achieve these facts," Hajizadeh said.

After the Iranian claims were made public Sunday, a U.S. official told ABC News that reverse engineering the drone would be a difficult feat, one even China would have a difficult time achieving.

According to Iran's Fars News Agency, many countries have asked for technical information about the Sentinel, "but Moscow and Beijing have been most aggressive in their pursuit of details."

The U.S. has asked for the drone to be returned, but Iran has refused.